1. Field of the Invention
The present invention relates, in general, to an apparatus for holding a coupling pin at a desired position in a pin-coupled structure, regardless of a relative movement of two or more coupled parts in the structure, and, more particularly, to a pin holding apparatus, which has two semicircular pin holding blocks with an elastic member interposed between the two pin holding blocks, and is inserted into a pin slot with the two holding blocks radially compressed by an external force to reduce the outer diameter of the apparatus, and elastically expands in the pin slot due to the restoring force of the compressed elastic member when the external force is removed, thus being set in an annular groove formed on the inner surface of the pin slot and holding a pin at its desired position in the pin slot.
2. Description of the Prior Art
As well known to those skilled in the art, a pin-coupled structure has been typically used in a variety of machines and other structures. In order to couple two or more parts of a machine or a structure to each other using a coupling pin in the prior art, a pin slot is formed at a desired position of each part. The parts are, thereafter, coupled together by inserting a coupling pin into the aligned pin slots of the parts. An example of such conventional pin-coupled structures is shown in FIG. 1.
FIG. 1 shows a breaker used as an attachment of a power excavator and having a conventional pin holding apparatus. As shown in the drawing, a breaker drill 103 along with a plurality of locking members is inserted into a drill hole of a drill support block 102, and is held at a desired position in the support block 102 by means of a plurality of pins 101 and stoppers 105. During a breaking work using the breaker, the breaker drill 103 generates intensive vibrations to loosen the pins 101. In an effort to hold the pins 101 in their positions regardless of such vibrations, the stoppers 105 are used. However, the stoppers 105 are also gradually loosened by such vibrations and cannot effectively hold the pins 101 in their positions for a desired lengthy period of time. In the pin holding apparatus used in this breaker, each of the stoppers 105 comprises a rubber peg driven into a pin slot after inserting a pin 101 into the pin slot, and the rubber peg is stopped using both a stop ring and a plug bolt.
As shown in FIGS. 2a and 2b showing a conventional pin holding apparatus used in such a pin-coupled structure, a snap ring 200 manufactured according to the Korean Industrial Standards, KS B 1336-85, is used as a stop ring. This snap ring 200 has a gap formed therein, thus having elasticity. That is, such a snap ring 200 is inserted into a pin slot 201 while being compressed, and is released in the pin slot, so the snap ring 200 elastically expands to restore its original shape, and stops a pin 202 in the pin slot 201. However, the thickness of the snap ring 200 is limited since it is very difficult to form an annular shape of the ring 200 with desired elasticity when the thickness of the ring 200 exceeds a predetermined level. Therefore, the snap ring 200 is somewhat thin, so the ring seat groove formed on the inner surface of the pin slot 201 for seating the ring 200 therein fails to have a desired effective depth.
In order to hold the pin 202 in the pin slot 201, the pin 202 is first inserted into the pin slot 201. Thereafter, a rubber peg 204 is driven into the pin slot 201 until it is positioned at the end of the pin 202. The snap ring 200 is, thereafter, set in the pin slot 201 to stop the rubber peg 204. However, when the pin 202 is repeatedly vibrated in such a pin-coupled structure, vibration impact is repeatedly transmitted to the snap ring 200 through the rubber peg 204, thus forcing the ring 200 to be removed from its original position and fail to stop the rubber peg 204. In such a case, the pin 202 may be undesirably removed from the pin slot 201, and disconnect the coupled parts from each other.
FIG. 3 shows another embodiment of conventional pin holding apparatuses. This conventional pin holding apparatus uses a spring pin 300 manufactured according to the Korean Industrial Standards, KS B 1339-85. In this pin holding apparatus, the spring pin 300 is manufactured by rolling a steel plate having elasticity allowing the pin 300 to be elastically compressed and expanded in a radial direction within a predetermined range. This spring pin 300 is forcibly fitted into a pin slot to accomplish a pin holding effect. However, this spring pin 300 undesirably gradually loses its original elasticity when it is used in a pin-coupled structure generating intensive vibrations for a lengthy period of time. In such a case, the spring pin may be unexpectedly removed from the pin slot, and fail to continue performing its pin holding function, thus disconnecting the coupled parts from each other.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a pin holding apparatus, which has two pin holding blocks with an elastic member interposed between the two pin holding blocks, and holds a pin at its desired position inside a pin slot by the protruding semicircular portions of the pin holding blocks set in an annular groove formed on the inner surface of the pin slot.
Another object of the present invention is to provide a pin holding apparatus, which is easily set in and removed from the pin slot.
A further object of the present invention is to provide a pin holding apparatus, which effectively holds the pin in the pin slot for a desired lengthy period of time regardless of vibrations of the pin-coupled parts, thus maintaining the stable coupling of the parts, and which has an elastic cushion positioned at the junction of the pin and the pin holding apparatus, thus almost completely preventing a breakage of the pin.
In order to accomplish the above objects, an embodiment of this invention provides an apparatus for holding a pin in a pin-coupled structure consisting of two or more parts each having a pin slot, with an annular groove formed on the inner surface of the pin slot at a position around an end of the pin slot, and a pin set in the pin slot to couple the parts to each other, wherein the apparatus comprises: two pin holding blocks each having a protruding portion on the external surface thereof and made of an incompressible material; and an elastic member interposed between the two blocks, whereby the apparatus is inserted into the pin slot while being compressed in a radial direction by an external force to reduce the outer diameter thereof, and is released from the external force, so the apparatus elastically expands by a restoring force of the elastic member and the protruding portions of the two blocks are seated in the annular groove, thus holding the pin in the pin slot without allowing the pin to be undesirably removed from the pin slot regardless of a relative movement of the pin-coupled parts.
Another embodiment of this invention provides an apparatus for holding a pin in a pin-coupled structure consisting of two or more parts each having a pin slot, with an annular groove formed on the inner surface of the pin slot at a position around an end of the pin slot, and a pin set in the pin slot to couple the parts to each other, wherein the apparatus comprises: two pin holding blocks each having a protruding portion on the external surface thereof and made of an incompressible material; an elastic member interposed between the two blocks; and an elastic cushion having a cross-section similar to that of the pin and covering the lower ends of the two blocks and the elastic member, whereby the apparatus is inserted into the pin slot while being compressed in a radial direction by an external force to reduce the outer diameter thereof with the elastic cushion coming into contact with an end of the pin, and is released from the external force, so the apparatus elastically expands by a restoring force of the elastic member and the protruding portions of the two blocks are seated in the annular groove, thus holding the pin in the pin slot without allowing the pin to be undesirably removed from the pin slot regardless of a relative movement of the pin-coupled parts.